| abstract |
A phosphor comprising: an α-type sialon crystal as a main component, wherein the α-type sialon crystal comprises: at least Eu; Ca; Si; Al; Oxygen; and Nitrogen, wherein the α-type sialon crystal is expressed by the general formula: ( Approx x , Eu y ) ( Si 12th - ( m + n ) Al m + n ) ( O n N 16 - n ) and m = δ M. × x + δ A. × y wherein the α-type sialon crystal is expressed by a compositional formula with parameters 'x', 'y', 'm' and 'n' meaning: 'x' an amount of a solid solution of Ca in a sialon Unit cell, 'y' an amount of a solid solution of Eu in the sialon unit cell, 'n' an amount of a content of oxygen in the sialon unit cell, and which are in a range expressed by: 0.2 ≤ x ≤ 2.4 0.001 ≤ y ≤ 0.4 0.5 × m < n ≤ 2 0.6 ≤ m ≤ 1.4 and 0.8 ≤ n ≤ 2 and wherein the phosphor emits luminescence having a peak in a wavelength range of 560 nm to 575 nm when irradiated with an excitation source. |